Propeller



Sept. 15, 1964 J. SKOPYK 3,143,736

PROPELLER Filed March 26, 1962 2 Sheetls-Sheet 1 INVENTOR.

Sept. 15, 1964 J. SKOPYK 3, 6

PROPELLER Filed March 26, 1962 2 Sheets-Sheet 2 INVENTOR.

United States Patent Office 3,143,73 PROPELLER Joseph Skopyk, 3911Bloor'St. W., Islington, Toronto 18, ()ntario, Canada Filed Mar. 26,1962, Ser. No. 182,484 Cla ms, (Cl. 170-176) This invention relates toimprovements in water propulsion devices and more particularly toimprovements in propellers.

It is well known that a great deal of propulsivepower is lost whenutilizing propellers, of the prior art due mainly to centrifugal forceapplied to the water in the vicinity of the propeller blades causingturbulence and cavitation.

Furthermore, due to the pressures at the tips of the blades, the tiparea is necessarily restricted in order to prevent such pressure indamaging the propeller.

It is, therefore, an object of the present invention to provide apropeller which will substantially obviate the movement away from thepropeller due to centrifugal force.

It is another object of the present invention to provide a propellerwhich will divert all the water rearwardly with a consequent forwardreaction being transferred to the propeller.

It is still another object of the invention to provide a propellerwhich, compared to conventional propellers may have an extremely largeblade area in comparison to its diameter and thereby absorb more enginepower and translate it into propulsive power.

A further object of this invention is to provide a propeller which, bysupporting the blade tips in a tunnel like housing, will also permit theformation of the blades in a highly efiicient but hitherto a practicalconformation.

It is yet another object of this invention to provide a propeller whichmay be adapted for use with either outboard or inbroad engines, asrequired.

These and other objects and features of this invention will becomeapparent when taken in conjunction with the accompanying drawings inwhich:

FIG. 1 is a part sectional, part sectional, perspective view of apropeller embodying the present invention adapted for use with aninboard engine.

FIG. 2 is a front end elevation of a propeller similar to thatillustrated in FIG. 1, adapted for use with an outbroad motor.

FIG. 3 is a sectional side elevation of the propeller illustrated inFIG. 2 taken on the line 33.

FIG. 4 is a fractional side elevation of the stern of a boat powered byinboard engines incorporating a propeller as illustrated in FIG. 1.

FIG. 5 is a fractional, side elevation of the stern of 'a boatpowered byan outboard motor by embodying a propeller as illustrated in FIG. 2.

Referring to FIG. 1, a propeller houses a plurality of substantiallyidentical blades 11 havingtheir 'root ends 12 firmly aflixed to acentral, substantially cylindrical hub 13 and their tips 14 beingattached to and supported by a tunnel member 15.

It will be noted that hub 13 is of substantially conventional designhaving a centre bore 16 and a keyway 17 formed therein, bore 16 beingadapted to slidably accommodate a drive shaft 18 and its attendant key19. Although not shown, propeller 10 is retained on shaft 18 byconventional nut and thread means located behind the rear surface 20 ofhub 13.

Referring also to FIGS. 2 and 3, a propeller 21 is similar in allrespects to propeller 10 as described with the exception of its hub 22which is adapted for attach- 3,148,736 Patented Sept. 15, 1964 ment toan outboard motor by means of two diametrically opposed threaded holes23 -23. The blades 11 and tunnel member 15 are however identical tothose described on propeller 10 and are numberedas such in FIGS. 2 and 3for clarity. V

Blades 11 are of generally volute configuration, hay: ing arcuateleading edges 24 substantially coplanar with The design of blades 11 issuch that water contained within tunnel 15 is caused to move rearwardlythereof during rotation of the propeller with the minimum of turbulence,the obliquity of the trailing edges 25 causing the water flowing throughthe unit to leave the vicinity of the blades progressively and therebysubstantially obviate the formation of swirl currents and the like whichnormally tend to decrease the efiiciency of conventional propellers.

Furthermore, the presence of tunnel 15 in addition to maintaining a fullbore of water around blades 11, directs the Water rearwardly in a jeteifect, thereby increasing the thrust available from propeller 10 or 21.

The truncated conical configuration of tunnel 15 as illustratedincreases this jet effect but the maximum efiicient degree of slope ofthe side walls thereof varies with the other design factors such aslength, diameter, and speed of operation.

It should also be noted that tunnel 15 may be of right cylindricalconfiguration which, although not as efficient as the conical design,still provides more useful work from a given power source than aconventional propeller, and, under certain circumstances, may be easierand cheaper to manufacture than the conical type.

FIG. 4 illustrates propeller 10 of FIG. 1 attached to a boat 30 equippedwith an inboard engine, shaft 18 thereof, as previously illustratedbeing the shaft provided originally with boat 30.

FIG. 5 shows propeller 21 of FIG. 2 attached to the outboard motor 31 ofa boat 32 by means of hub 22 as described, the positioning of threadedholes 23 allowing propeller 21 to be bolted to the propeller drivemechanism 33 in the conventional manner.

The general design of the individual parts of the invention as explainedabove may be varied according to requirements in regard to manufactureand production thereof, While still remaining within the spirit andprinciple of the invention, without prejudicing the novelty thereof.

The embodiments of this invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A propeller including a plurality of substantially identical blades;each of said blades having a root end, a tip, a leading edge and atrailing edge; a centre hub supporting said blades at said root ends; atunnel member supporting said tips; said tunnel member and said tipsbeing elongated rearwardly of said hub; said blades being of voluteconfiguration; said volute configuration extending at least half theinner circumference of said tunnel member; and means for attaching saidhub to conventional driving means.

2. A propeller as defined in claim 1 in which said leading edges of saidblades are substantially coplanar with ,3 Y Q the forward surface ofsaid hub and the forward edge of said tunnel member.

3. A propeller as defined in claim 1 in which said tip and said trailingedge of each of said blades spiral Iearwardly within said tunnel memberand converge at a point adjacent the rear edge of said tunnel member.

4. A propeller as defined in claim 2 in which said tip and said trailingedge of each of said blades spiral rearwardly within said tunnel memberand converge at a point adjacent the rear edge of said tunnel member.

5. A propeller as defined in claim 4 in which said tunnel member is oftruncated conical configuration, having wide and narrow open ends, saidwide end being foremost.

References Cited in the file of this patent UNITED STATES PATENTS ArnoldJune 18, 1912 Johannesen Sept. 8, 1959 Geske Ian. 1, 1963 FOREIGNPATENTS Great Britain 1868

1. A PROPELLER INCLUDING A PLURALITY OF SUBSTANTIALLY IDENTICAL BLADES;EACH OF SAID BLADES HAVING A ROOT END, A TIP, A LEADING EDGE AND ATRAILING EDGE; A CENTRE HUB SUPPORTING SAID BLADES AT SAID ROOT ENDS; ATUNNEL MEMBER SUPPORTING SAID TOPS; SAID TUNNEL MEMBER AND SAID TIPSBEING ELONGATED REARWARDLY OF SAID HUB; SAID BLADES BEING OF VOLUTECONFIGURATION; SAID VOLUTE CONFIGURATION EXTENDING AT LEAST HALF THEINNER CIRCUMFERENCE OF SAID TUNNEL MEMBER; AND MEANS FOR ATTACHING SAIDHUB TO CONVENTIONAL DRIVING MEANS.